Summer Retention Basins

     Today retention basins are required by law to be built near building construction.  The basins' job is to hold storm water so it doesn't wash out soil or fill waterways with silt.  Some human-made basins that hold water well, are like ponds attracting certain kinds of adaptable wildlife to the water, making those basins interesting.  And emergent cattails and crack willows, two of the first plants to colonize the shallow and damp edges of retention basins, when those plants are allowed to grow, attract other species of critters.  And the basins and the ground around them are usually planted to grass and trees, attracting lawn wildlife when the grass is regularly mowed.
     A family each of  Canada geese and mallard ducks live on and around some retention basins usually filled with water.  Both partners of a pair of Canadas raise four to six goslings while only hen mallards raise broods of about a dozen ducklings.  Goslings, like their parents, graze on short grass, while the ducklings feed on aquatic and terrestrial invertebrates and some plants.  Not all goslings and ducklings grow up because of the hearty appetites of snapping turtles, raccoons and mink in the water and hawks and red foxes on land.
     Green frogs and/or bull frogs are camouflaged on the edges of retention basins that generally are filled with water.  These frogs travel from pond to pond during rainy or dewy nights.  Males of green frogs and bull frogs gulp and moan respectively to attract mates for spawning thousands of eggs. 
     Frogs catch invertebrates by flipping out their tongues, which are attached to the front of their mouths.  The frogs' tongues snare the victims and flip them back into their mouths.  Tadpoles, however, eat algae and decaying plant and animal material.   
     Unfortunately for the frogs and their tadpoles, mink, raccoons, snapping turtles, great egrets and great blue and green-backed herons catch and consume many of those frogs and their tadpoles, but not all.  And dragonfly nymphs of a few kinds snare tadpoles to ingest them.  Surviving nymphs change to winged adults and buzz over water-filled retention basins as they do ponds to catch and eat flying insects.
     Cattails emerging from shallows on the edges of retention basins attract muskrats and red-winged blackbirds.  Muskrats eat the roots of cattails and pile chewed-off, cattail stems in the shallows to build protective homes with entrances under water.  The black, red-shouldered male red-wings repeatedly sing "konk-ga-reeee" from emergent, swaying cattail stalks to establish nesting territories and attract females for nesting.  And the chocolate and beige-striped female red-wings build grassy nurseries a couple of feet above the normal water level among those same cattails.  Fledged red-wing youngsters cling to cattails to be fed invertebrates by their parents. 
     Pairs of gray catbirds and yellow warblers nest among clumps of crack willow trees on the shores of some retention basins, as those birds do around certain ponds.  The catbirds often walk along the muddy edges of ponds and basins to watch for invertebrates to eat.  The warblers, which are yellow, consume invertebrates from the trees.
     The lawns and/or fields around retention basins harbor certain lawn and field birds and mammals.  Cottontail rabbits can be spotted grazing on grass on lawns.  But they seek shelter under planted shrubbery.  Killdeer plovers trot over the short grass to catch invertebrates in their beaks.  Occasionally, a pair or two of killdeer will hatch four young on bare or stony patches in the lawns.  American robins and purple grackles also move across lawns after invertebrates and nest in the planted trees.  And a pair or two of eastern kingbirds hatch offspring in open cradles in the trees and flutter out to snatch flying insects from mid-air, one at a time.      
     Barn swallows and tree swallows cruise swiftly after flying insects over certain retention basins and the lawns or fields around them.  The presence of barn swallows is decided whether or not barns or other buildings are close by.  And tree swallows are there if tree hollows or nesting boxes are nearby.
     These are all adaptable creatures around retention basins that can satisfy their needs.  Basins help increase the populations of those wild animals by providing them with more homes, nesting places and food.  Sometime, visit a basin to experience some of the attractive and interesting critters around it.